1. Field of the Invention
The present invention relates to a reflective/transmissive scanner with a removable scanning platform and a docking port. More particularly, the present invention relates to a scanner which reduces the number of times that light must pass through a transparent plate during the scanning of an object, thereby improving the quality of the scanned image.
2. Description of the Related Art
Recent developments in the use of high speed, low cost digital electronic imaging systems to process, transmit and display digital information have substantially increased the demand for optical scanners to convert information into digital electronic form. A variety of optical scanners, including facsimile machines and digital copiers, have been developed to meet this growing demand. There are generally two types of scanners: reflective scanners for scanning opaque objects, such as documents and photographs; and transmissive scanners for scanning transmissive objects, such as slides and transparencies. Reflective scanners project light onto the surface of the object to be scanned. The light reflected from the opaque object is then received by an image-retrieving device which converts the image of the scanned object into an electronic signal. Transmissive scanners project light through the object to be scanned. The light passing through the transmissive object is then received by an image-retrieving device which converts the image of the scanned object into an electronic signal. The growing demand for both reflective and transmissive scanners has resulted in a need for scanners to provide both capabilities.
FIG. 1a illustrates the path of light during the scanning of an opaque object 1 positioned on the transparent plate 2. As illustrated by the arrows, light emitted from the light source 3 (typically located in the base of the scanner) passes through the transparent plate 2 and is reflected by the surface of reflective object 1, whereupon it passes back through the transparent plate 2 again and is then received by the image-retrieving device 4. In this example, light must pass through the transparent plate 2 twice. The physical properties of the transparent plate 2 can cause distortion of the light; therefore, the quality of the obtained image is degraded.
FIG. 1b illustrates the path of light during the scanning of a transmissive object 13 positioned on a transparent plate 14. As illustrated by the arrows, the light emitted from the light source 11 first passes through a transparent cover plate 12, then passes through the transmissive object 13 and the transparent plate 14 and finally be received by the image-retrieving device 15. Typically, the light source 11 is located in the lid of the scanner whereas the image-retrieving device 15 is located in the base of the scanner. The cover plate 12 can protect the light source 11 from dust or other damage. In this case, light must pass through both the cover plate 12 and the transparent plate 14. The physical properties of these two transparent plates can cause distortion of the light; therefore, the quality of the obtained image is degraded.